La_(0.2)Sr_(0.8)Co_(0.8)Fe_(0.2)O_(3-z)钙钛矿型混合导电体透氧性能  

OXYGEN PERMEATION OF La 0.2 Sr 0.8 Co 0.8 Fe 0.2 O 3-z MIXED CONDUCTING PEROVSKITE CERAMICS

作　　者：陶顺衍[1] 张华[1] 陆天长[1] 杨南如[1] 

机构地区：[1]南京化工大学材料科学与工程系

出　　处：《南京化工大学学报》1998年第2期39-43,共5页Journal of Nanjing University of Chemical Technology(Natural Science Edition)

基　　金：国家自然科学基金

摘　　要：以稳态法（ＳｔｅａｄｙＳｔａｔｅＰｅｒｍｅａｔｉｏｎＭｅｔｈｏｄ）对Ｌａ０．２Ｓｒ０．８Ｃｏ０．８Ｆｅ０．２Ｏ３－ｚ（ＬＳＣＦ）混合导电体在８５０℃～７００℃间的透氧性能作了测试；同时，以暂态热重法（ＴｒａｎｓｉｅｎｔＴＧＡ）研究了ＬＳＣＦ在８１５℃Ｏ２→Ｎ２→Ｏ２交变气流中的脱氧、吸氧过程，并对其透氧性能作了估算。结果表明，ＬＳＣＦ是一种具有实际应用价值的致密透氧膜；在暂态热重测试条件下，ＬＳＣＦ的吸氧、脱氧过程是可逆的，且整个表面反应受氧脱附过程控制；由暂态热重数据估算出的材料透氧性能比稳态法的推算值低，其值分别为１．５６×１０－７ｍｏｌ／ｃｍ２·ｓ和６４０×１０－６ｍｏｌ／ｃｍ２·ｓ。The rates of oxygen permeation through mixed conducting La 0.2 Sr 0.8 Co 0.8 Fe 0.2 O 3-z (abbreviated as LSCF)was measured in a temperature range 850 ℃～700 ℃ by steady state permeation method. The oxygen desorption and absorption of LSCF at 815℃ in O 2→N 2→O 2 cycling atmosphere were studied by transient TGA method, and the oxygen permeation flux of LSCF was estimated. Results showed that LSCF was a promising dense oxygen permeation membrane.The process of oxygen desorption and absorption of LSCF under the measuring condition of transient TGA method were reversible, and the surface exchange was controlled by the oxygen desorption. The estimated value of oxygen permeation flux by transient TGA method was less than that calculated in steady state measuring,which were 1.56×10 -7 and 6.40×10 -6 mol/cm 2·s,respectively.

关 键 词：钙钛矿型 混合导电体 LSCF 透氧膜 

分 类 号：TQ028.2[化学工程] TQ028.8